Master switch assembly



May 15, 1956 P. v. YlNGsT 2,745,916

MASTER SWITCH ASSEMBLY Filed June 30, 1953 2 Sheets-Sheet l INVENTOR. .--n1/U- i., M 1` TLIU I Pau( l/ Yzngai l L'i L); u l f" I "l l g BY /4/ /5 I; l )I l 2 3 TT YS May 15, 1956 P. v. YINGST 2,745,916

MASTER SWITCH ASSEMBLY Filed June 50, 1953 2 Sheets-Sheet 2 /z 56' C] A o p o a IN V EN TOR.

United States Patent O MASTER SWITCH ASSEMBLY Paul V. Yingst, Cincinnati, Ollio, assignent() The Post Glover Electric Company, Cincinnati, Glaxo, a corporation of Ohio Application .lune 30, 1953, Serial No. 365,045

6 Claims. (Cl. 2200-17) The present invention relates to master switches of sturdy construction for general application in mill service and the like to control a selected number of electrical circuits in predetermined sequence from one location.

An object of the invention is to provide a compact but easily assembled master switch structure that'may be used singly or in ganged arrangement in a minimum of longitudinal mounting space and on a common base under a common closure.

Another object is to provide master switch units each affording a plurality of operating cams operating in unison, with each cam controlling a plurality of contacts for controlling a large number of circuits in a selected predetermined sequence.

Still another object of the invention is to provide switch units of the indicated character having a conveniently limited amount of operating lever movement substantially within the body lines of the unit and to further provide for ganged mounting thereof on a common base with a relative gain in space saving for each unit added to an initial master switch unit.

A further object of the invention is to provide an assembly of self-centering and self-aligning sturdy precision parts for each unit or ganged multiple thereof and which may be economically constructed with a minimum of skilled labor and supervision.

These and other important objects are attained by the means described herein and exemplified in the accompanying drawings, in which:

Fig. 1 is an end elevational view of a master switch assembly of the invention with the closure shown partly in dotted lines and partly in cross section.

Fig. 2 is a side elevational View of the device of Fig. l, parts being broken away.

Fig. 3 is a cross sectional view taken on line 3-3 of Fig. 2.

Fig. 4 is a cross sectional view Fig. 2.

Master switches of general application in mill service, for example are subjected to hard usage and often abusive handling, but are required to operate reliably and accurately. Where a large number of electrical circuits must be controlled conveniently at an operators station in limited space the problem ofrganged mounting of master switches has heretofore presented diiculties and disadvantages that are eliminated by the use of the hereinafter described construction. v

In the illustrated embodiment a base is provided with a completely removable closure cover 11 retained by suitable latches 12. The width and height of the base and cover remains constant for single units or ganged units while the length of each is increased to accommodate the assembly at hand. Each added unit, after the rst, requires a lesser longitudinal mounting space than said rst unit in the ganged assembly on a common base.

The base 10 is precision drilledA according to pattern for mounting the selected one or more master switch units taken on line 4 4 of ice thereon, and at opposite sides of each switch location it has suitable tapped holes for receiving threaded wiring conduits (not shown) or pipe plugs 15 if conduits are not placed in the holes, locknuts 13 or 14 being employed to further secure any of such members. This will exclude entry of dust and moisture beneath the cover. Closely adjacent the longitudinal edges of base 10 are holes 16 to receive hold-down bolts 160.

The single center foot 17 of each of two or more mounting stands 18 has a true plane bottom surface whereby the stands are mounted in parallelism on top of the base by bolts 19 passing through holes 2l) in the base and into threaded bores 21-21 in each foot 17. I prefer to nish a longitudinal center strip area on 'the top of the base wide enough to properly seat the feet 17.

Stands 18 are identical in size and shape. these stands are employed for a single unit or first unit in a ganged series. In the ganged mounting only one of the stands 18 is required for each of the added units so that an appreciable economy of longitudinal mounting space results.

Each stand 18 has a center bore 22 midway its lateral edges at a short distance below the horizontal top edge 23 in order that two, three or more of said stands may receive therein a common stationary shaft 24 in parallelism with the longitudinal center of base .10. One endmost stand 18 has a setscrew 25 passing through the edge 23 and into binding relation with shaft 24. Each additional stand 18 has secured on its top edge 23 a star wheel segment 26 held by screws 27 in counter-drilled holes 28 in an edgewise upright position.

The star Wheel has, in this instance, a series of eight notches 29 formed along a radius with the center axis of shaft 24, four of said notches being on each side of a perpendicular plane to the base in which plane the center axis of said shaft lies. In the present embodiment notches 29 have their low centers spaced six and one-fourth degrees (GIAN) apart and as will be hereinafter made apparent said notches serve to provide a vertical center holding position for an operating lever 30 of a movable cam assembly 31 and six circuit closing positions on each side of said center position.

The upper corners of stands 18 are cut away at equal opposite angles to accurately support terminal mounting strips 32-32 which are secured by bolts 33 passing therethrough into accurately tapped holes 34 in the edges of two or more of the parallel stands. In this manner each strip has one longitudinal edge in relatively close parallel relation to the center axis of shaft 24. In a generally similar manner the lower corners of the stands are cut away and a second pair of terminal strips 32-32 are mounted and the nearest longitudinal edges thereof to the shaft are in equally spaced parallelism with the corresponding edges of the first mentioned top terminal strips Two of for the Each terminal strip 32 has secured thereto three double break spring closed contact assemblies 35 in uniformly spaced relation intermediate the adjacent faces of adjacent stands 18 so that a maximum ot twelve circuits can be controlled by each master switch unit. lFour of these contacts 35 on the respective terminal strips are grouped about each of three cams 36 of the moving cam assembly 31. Assemblies 35 each include a pair of contact studs 37-37 lixedly secured in a strip 32 and having wiring terminal ends 371) projecting through it for easy access on the exposed face of the strip. Assemblies 35 each also include a pedestal mounted pivotal arm 38 with its pivot parallel to the center axis of the shaft and carrying on one end a bridging Contact 39 while the other end has a cam roller 40 that is spring urged against the circumference of a cam disc 36 which holds the contact .in open circuit position until, on rotation of the cam a centers of notches 29 of the star Wheel effects a corresponding circumferential movement of the cam relative to each of the four rollers 40. There is thus provided, onV the edge of the cam, four non-overlapping portions, each having a given central point of tangency With a roller -40 and on each side thereof six equally spaced points that may be .centers for a short notch 41, or the beginning or the end of full seating contact of a roller 40 in a long notch 42.

The movable canrassembly 31 includes a hub assembly piece A43 on which the cams are concentrically supported for rotation as a unit about the stationary shaft 24. Piece '43 comprises an elongated hub 44 that is square in cross section and has an axial bore 45 therethrough. Into the opposite ends of bore 45 `are pressed tubular bearings 46 which journal the assembly on shaft 24. Near one end of hub 44 is a rigid radially disposed arm 47, one face of which is disposed in closely spaced parallelism with the Aadjacent face of star wheel 26 on the associated mounting stand 18. Thel outer end of radial arm 47 has an angularly turned extension 48 in parallel spaced overhanging relation to hub 44. Extension 48 has a bore 49 to receive one end i) of operating lever 30. The end of the extension is slotted at 51 into the bore 49 and a binding screw 52 is employed in known fashion to draw the split vend of the extension together for removably securing the operating lever in the bore. A saddle piece 53 is secured on top of the extension and overhangs the top of the star wheel 26. A pair of spring pressed arms 54 are pivoted in the saddle piece and carry detent rollers 55 on their free ends for yieldably seating in the two endmost notches 29 of the star wheel segment to cooperate therewith as a self holding ratchet and detent to position radial arm 47 and cooperating lever 30 in a vertical center position which is pronouncedly indicated to the operator as the two rollers 55 simultaneously enter or leave the two notches when the operating lever is manually moved in either direction.

When the lever and radial arm 47 are moved in either direction out of center position the leading roller 55 leaves its endmost notch 29 and rides onto the unnotched inclined edge 56 of the star wheel segment, While the trailing roller 55 at the opposite side will move from its endmost notch 29 successively into the intermediate six notches 291 and provide corresponding individual holding points for each of the contact rollers on y the individual portions of the cams 36 on which they act. If the operating lever is returned to center and is moved beyond center position the detent rollers afford an additional six holding positions with a corresponding number of additional holding points for each contact roller 40 on its cam. The operator in manipulating the lever 30 thus has a tactual indication of the center position and of each of thesix holding points on each side of center position.

The star wheel 26 has a series of threaded holes h to selectively receive stop pins p in order to limit movement of radial arm 47 as desired in either direction to selected positions and to thus limit the travel of the trailing roller up to and into any selected star Wheel notch 29. y l

In order to utilize a large percentage of the total circumference of each cam 36 in which to distribute thirteen holding points for each of thefour contact rollers 40, I prefer to establish an indexing point 58 on the circumference of each cam at a given end of a predetermined diameter X thereof and to progressively establish the holding points about the circumference in both directions from the indexing point. This facilitates the selective notching of the several cams in order to attain a circuit closing contact sequence to fulfill the requirements of a customer as indicated by his wiring diagram. Such selective notching can be effected on any suitable notch cutting or grinding machine equipped with any suitable indexing head such as are available in the arts. For this reason the cams 36 are arranged to be irreversibly mounted in cam assembly 31 as well as in a similarly arranged jig for an indexing head of a notch forming machine. To attain precision parts that infallibly operate in the switch unit even with relatively untrained assembly labor the cam assembly is arranged as follows:

Each cam 36 has an enlarged center hole 5'/ that freely passes the square hub 44. A single bolt hole 59 is located quite close to center hole 57 and is centered on diameter X between indexing points 58 and said center hole. On the opposite side of center hole 57 and equidistant on opposite sides of diameter X are two bolt holes 60-60. Beyond the bolt holes 60-60 and on one side of diameter X is a locator hole 61.

The hub 44 has tixedly centered thereon a square metal plate 62 which is also welded to radial arm 47. Fixed plate 62 is drilled in the opposite upper corners to correspond with bolt holes 60 in the cam. The radial arm 47 has a locator rod 63 positioned to correspond to and enter the locator hole 61 in the cam. The cams 36 are thus irreversibly assembled onfcam assembly 31 by passing bolts 64-464 through the corresponding holes 60 in the cam and through the holes in the upper corners of .the plate 62 while the locator rod 63 passes through locator hole 61 in each cam, A third bolt 65 passes through bolt hole 59 in each cam and a corresponding hole in plate 62. This constitutes a fool proof irreversible positioning of the cam with a predetermined face of each facing toward the radial arm and with its index- .ing point 58 diametrically opposite the end of the radial arm. A removable plate 66 has a center bore to pass shaft 24 and abut the free end of hub 44. The free end of hub 44 has in one diagonally opposite pair of corners a pair of socket holes 67 which receive xed studs 68 on the face of the removiable plate 66 and serve to locate the edges of the plate in parallel relation to corresponding edges of fixed plate 62. The removable plate has holes corresponding to the bolt holes in the cams and in the xed plate. The heads of bolts 64 and 65 are countersunk in the outer face of removable plate 66 and nuts 70 are applied on the free ends of the bolts and are drawn up tightly against the plate 62 after the cams lareassembled thereon with spacers 69 thereon between the adjacent cams. The removable cam assembly may be secured together as a rigid unit and after placing a spacer 71 on the shaft 24 against the stand 18 the assembly 31 may be slid onto the shaft. Thereafter a second stand 18 carrying a star wheel 26 may be slid onto the shaft and then bolted to the base. When the three properly notched cams of each master switch unit are properly assembled andthe single unit or ganged multiple units are complete the wire connections according to cus-` tomers wiring diagram is quickly concluded in a neat and orderly fashion with six pairs of circuit wires (not shown) connected to each side of each switch unit and passed .in group through the adjacent hole in the base 10 and through suitable conduits that are firmly secured in the base by said locknuts 13 or 14.

The operating lever rod 30 is secured in position in I the extension of the radial arm and then passed through aslot in cover 11 which is arranged with a slot closing ystrip shiftable with the operating lever in any suitable manner for example as shown in U. S. Pat. No. 2,150,838.

e Handle knob 72 is screwed onto the external end of lever 30jafte'r'the cover 11 is in place on the base. The length of'the operating lever may be as great as is desired and if initially too long the end 50 may be cut off as desired to shorten it and it is easily secured in the split end of extension 48. The lateral space required for maximum movement of the lever 30 in both directions need be no greater than the width of the base 10.

The compact assembly in ganged relation of two or more master switches on a single base disposes the adjacent operating levers 30 close together for convenient access to the user in a minimum of space so that four of the master switches on a single base would have all of the levers 30 spaced apart at uniform distances of the order of less than five inches and the endmost levers spaced at somewhat less than that distance from the extreme ends of the base.

The invention will be understood as not limited to a specific number of notches in the star wheel since they may be varied if desired particularly if the number of contact roller positions required on the several cams 36 of one or more master switches would so indicate.

The adaptation of the master switches to individual mounting or to compact and enclosed ganged mounting involves only the proper selection of the length of the stationary shaft and of the base and cover. The simplified construction can be utilized for an increased number of cams and contacts per switch with a minimum of cost and effort.

What is claimed is:

l. A master switch construction comprising a base, a pair of centrally footed stands secured in spaced parallelism thereon, a stationary shaft supported parallel to the top of the base by said stands, terminal strips each secured on the edges of the stands with a longitudinal corner edge thereof parallel to and equally spaced from the center axis of the shaft, a plurality of spring closed contact assemblies mounted on each strip in spaced apart relation between said stands, each of the contact assemblies including an arm pivoted on an axis parallel to the shaft and having the free end thereof biased toward the shaft, a movable cam assembly including an elongated hub journaled on the shaft between the stands and provided adjacent its opposite ends with a fixed plate and a removable plate respectively,spaced parallel cam discs freely surrounding said hub, bolts passing through said plates and cams, spacers on the bolts between the cams and cooperating with the bolts to secure the cams in parallelism for unitary rotary movement with the hub, each cam presenting its periphery to the free end of a contact arm on each of the terminial strips at predetermined circumferentially spaced apart positions on the cam, a radial arm fixed to the hub and to the fixed plate thereon and operable in closely spaced parallelism to the adjacent mounting stand, a star wheel segment secured edgewise to the top edge of the said adjacent mounting stand, a saddle piece including a pair of spring pressed arms having rollers on their free ends for engaging the notches in the star wheel segment for yieldably holding the radial arm selectively in a verticial upright position and in a predetermined number of angularly related positions on either side of said vertical upright position, the cams being selectively notched for receiving the free ends of the contact arms whereby the several contacts are permitted to assume circuit closing positions in selected sequence with relation to other contacts associated with the same cam and with other cams in the switch.

2. A master switch construction comprising a base, a pair of centrally footed stands secured in spaced parallelism thereon, a stationary shaft supported parallel to the top of the base by said stands, terminal strips each secured on the edges of the stands with a longitudinal corner edge thereof parallel to and equally spaced from the center axis of the shaft, a plurality of spring closed contact assemblies mounted on each strip in spaced apart relation between said stands, each of the contact assemblies including an arm pivoted on an axis parallel to the shaft and having the free end thereof biased toward the shaft, a movable cam assembly including an elongated hub journaled on the shaft between the stands and provided adjacent its opposite ends with a fixed plate and a removable plate respectively, spaced parallel cam discs freely surrounding said hub, bolts passing through said plates and cams, spacers on the bolts between the cams and cooperating with the bolts to secure the cams in parallelism for unitary rotary movement with the hub, each cam presenting its periphery to the free end of a contact arm on each of the terminal strips at predetermined circumferentially spaced apart positions on the cam, a radial arm fixed to the hub and to the fixed plate thereon and operable in closely spaced parallelism to the adjacent mounting stand, a star wheel segment secured edgewise to the top edge of the said adjacent mounting stand, a saddle piece including a pair of spring pressed arms having rollers on their free ends for engaging the notches in the star wheel segment for yieldably holding the radial arm selectively in a vertical upright position and in a predetermined number of angularly related positions on either side of said vertical upright position, the cams being selectively notched for receiving the free ends of the contact arms whereby the several contacts are permitted to assume circuit closing positions in selected sequence with relation to other contacts associated with the same cam and with the other cams in the switch, the points of contact of the arms on the cams, when the radial arm of the movable cam assembly is in a vertical center position, defining individual neutral points peripherally spaced about the cam for the individual pivoted arms, said cams being selectively notched at selected predetermined peripheral points on either side of said neutral points to correspond with selected holding positions of the radial arm with respect to the star wheel.

3. A master switch construction comprising a fiat base, a first centrally footed mounting stand secured transversely of the base at one end thereof, a stationary shaft, said stand having a bore intermediate its lateral edges for receiving one end of a stationary shaft and positioning said end at a predetermined distance above the base, a movable cam assembly including an elongated hub journaled on the shaft, a fixed plate on the hub adjacent one end thereof, a removable plate on thev other end of the hub, said plates having a plurality of matching bolt holes, a plurality of cams and intermediate spacers therefor supported on the bolts between said plates whereby the cams are fixed to rotate with the hub in predetermined spaced parallel relation, a radial arm xed to the hub and its fixed plate, a locater rod secured in one face of said arm beyond the fixed plate and passing eccentrically through all of the cams whereby the cams are irreversibly mounted in the cam assembly, a second mounting stand secured on the base in parallelism with the first mentioned stand and supporting the shaft adjacent the last mentioned end of the hub, a star wheel segment fixed to the top horizontal edge of the last mentioned stand, said star wheel having a predetermined number of notches on either side of a vertical plane passing through the center axis of the shaft, spring pressed roller detent arms carried by the radial arm and in cooperative relation to the star wheel and permitting manual rotation of the movable cam assembly with predetermined self holding position wherein one of the detent rollers is selectively seated in any of the star wheel notches.

4. In a master switch construction a base predrilled for the reception of separately removable mounting ystands at established intervals along its stop center, at least two mounting stands mounted on the base at such intervals and removably secured to the base in parallelism to each other, a shaft supported by said stands in parallelism with the center line of the base and secured against movement in one of the stands, terminal mounting strips securedv respectively'to the edges `of all of the stands and presenting longitudinal corner edges in uniformlyY spaced parallelism with the center axis of the shaft, contact assemblies secured to the terminal strips atA predetermined intervals between the mounting stands, a star wheel segment fixed upright on the top edge of a mounting stand and provided with' a Series of notches disposed in part on opposite sides of a vertical plane in which the center axis of the shaft is lo'- cated, and a movable cam assembly rotatably journaled on the shaft and including a hub having a fixed plate at one end adjacent the said star wheel, a fixed radial arm on the hub operable in a plane immediately alongside the said star wheel and its supporting stand, a pair of roller arms on said radial arm biased to seat their several rollers in the endmost notches of the star wheel for positioning the radial arm in a vertically upward radial relation to the shaft, a removable plate positioned on the end of the hub opposite said fixed plate, a plurality ofl peripherally notched cam discs concentric with the hub and cooperating with the contacts on the terminal strips, the radial arm having a locater rod fixed at one end thereto and extending parallel to the shaft beyond said xed plate, the plates and cams being correspondingly drilled for the reception of bolts whereby the removable plate is secured on the end of the hub and the cams are positioned concentrically of the shaft for rotation with the hub, said cams also bored correspondingly for the receptionof the locater rod to afford irreversible mounting of the cams on the hub.

5. In a ganged master switch structure, an end mounting stand, a'shaft supported at one end in said stand and fixed against movement therein, a first cam assembly journaled on the shaft and having one end adjacent said stand, a second mounting stand having a fixed star wheel segment on its top edge, said second stand supporting said shaft adjacent the remaining end of the rst cam assembly, a second cam assembly journaled on the shaft and having one end adjacent said second stand, a third mounting stand having a xed star wheel segment on its top edge and supporting the shaft adjacent the remaining end of the second cam assembly, additional cam assemblies and mounting stands arranged alternately on and along the shaft as required, the cam assemblies each having on one end a radial arm with a roller detent means mounted thereon in cooperative and overhanging relation Cil 8 Y v to the several star wheel segments on the several mounting stands, a plurality of terminal strips substantially'coextensive with the shaft and parallel thereto and secured along the edges of all of the mounting stands, each carn assembly including a plurality of parallel cam discs rotatable to predetermined positions, each terminal strip'supporting a plurality of contact assemblies including contact rollers cooperatingl with selected peripheral sections of the associated cam discs, all of the mounting stands being uniformly footed, and a base predrilled for the reception of securing means whereby the stands are attachable in parallelism to the top of the base.

6. In a device of the class described the combination with ay base and a transversely slotted cover removably secured thereon, of a pair of centrally footed mounting stands removably secured in upright parallel relation on said base with the vertical centers of the stands substantially midway the longitudinal side edges of the base, a stationary shaft extending through said stands and supported thereby parallel to the top longitudinal center of the base, a cam assembly journaled on the shaft and having its opposite ends adjacent the adjacent sides of said stands, said cam assembly including a plurality of parallel cam discs in predetermined spaced relation, a plurality of terminal strips secured on the edges of the mounting stands in equi-spaced parallel relation about the shaft, each terminal strip having mounted thereon contact assemblies `cooperating with the respective cam discs, a radial arm fixed to the cam assembly and forming part thereof and having an offset overhanging the discs, an operating lever supported in the offset of the radial arm and extending radially of the contact assembly land through the transverse slot in the cover, a star wheel segment secured in upright relation to the top edge of the stand adjacent said radial arm and a spring urged cooperating detent roller mechanism secured on the radial arm adjacent the offset for yieldably retaining the cam discs in rotatably adjusted positions.

References Cited inthe file of this patent UNITED STATES PATENTS 1,718,478 Morse lune 25, 1929 2,530,974 Krapf et al Nov. 2l, 1950 FOREIGN PATENTS 601,139 Great Britain Apr. 28, 1948 

